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| author | Evan Cheng <evan.cheng@apple.com> | 2009-01-23 05:48:59 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2009-01-23 05:48:59 +0000 |
| commit | c212aa822cf9a01eb1b190e3fcdb62b327303ec1 (patch) | |
| tree | 533d3ace8f1a8aa6623852c1393360c6d190fc61 /lib/CodeGen/SimpleRegisterCoalescing.cpp | |
| parent | 5ed30619a81949a67a637afee64ed8c80f2a1e62 (diff) | |
| download | external_llvm-c212aa822cf9a01eb1b190e3fcdb62b327303ec1.tar.gz external_llvm-c212aa822cf9a01eb1b190e3fcdb62b327303ec1.tar.bz2 external_llvm-c212aa822cf9a01eb1b190e3fcdb62b327303ec1.zip | |
Only check if coalescing is worthwhile when the result is targeting a more restrictive register class.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62837 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/SimpleRegisterCoalescing.cpp')
| -rw-r--r-- | lib/CodeGen/SimpleRegisterCoalescing.cpp | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp index f0b0d58d13..f3ffc69ccc 100644 --- a/lib/CodeGen/SimpleRegisterCoalescing.cpp +++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp @@ -1290,8 +1290,13 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) { } } + // If we are joining two virtual registers and the resulting register + // class is more restrictive (fewer register, smaller size). Check if it's + // worth doing the merge. if (!SrcIsPhys && !DstIsPhys && - !isWinToJoinCrossClass(LargeReg, SmallReg, Limit)) { + (isExtSubReg || DstRC->isASubClass()) && + !isWinToJoinCrossClass(LargeReg, SmallReg, + allocatableRCRegs_[NewRC].count())) { DOUT << "\tSrc/Dest are different register classes.\n"; // Allow the coalescer to try again in case either side gets coalesced to // a physical register that's compatible with the other side. e.g. |